Neutral failure in a three phase power supply can be very dangerous and can also ruin valuable equipment. There are many causes of neutral failure. These include: bushing failure or neutral line breakage at the 3-phase distribution transformer, a broken neutral on an overhead distribution line, a broken service neutral conductor, a high ground resistance at the distribution transformer, the sharing of neutrals in a poorly wired building, overloading and unbalanced distribution, and, in general poor maintenance, such as inadequate tightening of connectors.